1. Field of the Invention
The present invention relates to a toner cartridge in relation to an image forming apparatus using an electrophotographic process such as a digital copying machine, a printer and a facsimile apparatus, and more particularly a toner cartridge detachably connected to a developing apparatus.
2. Description of the Related Art
In a generally-used image forming apparatus, for the purpose of simplifying an operation of replenishing toner, a toner cartridge which is filled with toner in advance and is detachably mounted to a developing apparatus, is used, and which toner cartridge can be replaced with a new one when all the toner stored in the toner cartridge is used up.
However, recycling of resources has been drawing more attention than ever. An increasing number of image forming apparatuses using an electrophotographic process have been equipped with a so-called toner recycling function in which left-over toner on a photoconductor drum after an image transfer process is removed by a cleaner and collected as used toner to be reused in the developing apparatus. By using such a function, it is possible to extend a replacement cycle of toner cartridges.
In a conventional image forming apparatus having the toner recycling function shown in FIG. 5, fresh toner is supplied from a toner cartridge 101 detachably mounted to a developing apparatus 100. Further, used toner in the developing apparatus 100 is collected in a process unit 102, and is released to a releasing portion 103 of the process unit 102. The used toner released at the releasing portion 103 is conveyed to the developing apparatus 100 through a conveying path 104.
Further, as shown in FIG. 6, there is another prior art providing a structure that a downstream end of a toner supplying path 105 extended from the toner cartridge 101, in which fresh toner passes through, is connected to a downstream end of a conveying path 104 extended from the process unit 102, so that the fresh toner is joined with the used toner and the joined toner is then supplied to the developing apparatus 100.
In the former prior art, the collected used toner is supplied to the developing apparatus 100 without any treatment. In this case, it is difficult to sufficiently mix the fresh toner with the used toner within the developing apparatus 100. In the latter prior art, the collected used toner and fresh toner are joined together to be supplied to the developing apparatus 100. However, in this case, too, the mixing process of the joined toners depends on an agitating operation within the developing apparatus 100. Accordingly, it is also not easy to obtain a preferable mixing state.
Japanese Unexamined Patent Publication JP-A 9-212055 (1997) discloses a construction for actively mixing both toners as shown in FIG. 7. In this construction, a toner mixer 106 is provided to mix the used toner t released from the process unit 102 with the fresh toner T supplied from a toner cartridge main body 101A. In this case, toners T, t mixed inside the toner mixer 106 are supplied to the developing apparatus 100.
However, in the construction of the above publicly known example, the toner mixer 106 is provided separately from the toner cartridge main body 101A so that an additional accommodation space must be created, and thus the entire structure becomes large. As such, it is not likely to willingly adopt such a construction.
In consideration of such a situation, Japanese Unexamined Patent Publication JP-A 9-251230 (1997) discloses a construction as shown in FIG. 8. In this construction, a used toner collecting port 110 is formed in a lower portion of a side wall 101a of the cartridge main body 101A, and a toner replenishing port 111 is formed in a bottom wall 101b of the cartridge main body 101A. A toner agitator 112 and a rotating body 113 for conveying toner are arranged within the cartridge main body 101A. The used toner t conveyed from the used toner collecting port 110 by a toner taking-in mechanism 114 is mixed with the fresh toner T by the toner agitator 112. The mixed toner is supplied to the developing apparatus 100 through the toner replenishing port 111 by the rotating body 113 to replenish the toner.
In the case of JP-A 9-251230, it may be possible to downsize the construction, however, the used toner collecting port 110 arranged in the lower portion of the side wall 101a of the cartridge main body 101A requires an additional structure of taking-in mechanism 114 in order to convey the used toner t in a horizontal direction from the used toner collecting port 110. Further, as a result of such a structure, it is also required to provide additional structures such as a sealing mechanism, resulting in complication of the entire structure. Further, since the used toner t is conveyed horizontally, there is such a problem that reliable agitating and mixing states cannot be obtained easily unless a moving direction of the toner agitator 112 and so on are adequately set.
Further, as shown in FIG. 9, Japanese Unexamined Patent Publication JP-A 5-80653 (1993) discloses a seal member 204 provided in a toner hopper 201, wherein one end of the seal member 204 blocks a toner supply port 202 and the other end thereof is secured to a rotary shaft 203a of an agitating member 203. When the invention is used, the seal member 204 is rolled up by rotating of the agitating member 203.
However, in the construction of JP-A 5-80653, the seal member 204 rolled up by the agitating member 203 is collected inside the toner hopper 201. In this case, there is a possibility that the sealing member is subject to sag or peel off during rotation of the agitating member 203, which will result in a deficiency in toner agitating and conveying properties.
An object of the invention is to solve the above problems and to provide a toner cartridge having excellent toner agitating and mixing properties. The toner cartridge results in improved image quality without increasing in complexity of the structure as well as being compact.
In order to solve the above-mentioned problem, the invention has the following construction.
The invention provides a toner cartridge detachably mounted to a developing apparatus, comprising:
a cartridge main body for containing toner, having a used toner recycling opening formed in an upper portion thereof via which conveyed used toner is dropped by gravity and is received into the cartridge main body, the toner cartridge being mounted to the developing apparatus in a state where the cartridge main body is filled with toner;
toner agitating means arranged within the cartridge main body, for agitating and mixing used toner and fresh toner; and
toner supply means arranged within the cartridge main body, for supplying agitated toner to the developing apparatus via a toner supply opening formed in the cartridge main body.
According to the invention, the conveyed used toner drops by gravity into the cartridge main body from the used toner recycling opening in the upper portion of the cartridge main body. Accordingly, the fresh toner and the used toner are efficiently agitated and mixed by the toner agitating means arranged within the cartridge main body. The agitated and mixed toner is supplied to the developing apparatus through the toner supply opening by the toner supply means arranged within the cartridge main body. Thus, a sufficient toner mixing state is obtained on a toner cartridge side without entrusting the agitation and mixture of the toners onto a developing apparatus side.
According to the invention, the used toner drops by gravity from the used toner recycling opening in the upper portion of the cartridge main body storing the fresh toner. Further, the toner agitating means and the toner supply means for supplying the mixed toner to the developing apparatus are arranged within the cartridge main body. Thus, the toner can be sufficiently mixed and agitated on the cartridge main body side without entrusting the mixture and the agitation onto the developing apparatus side. Further, it is possible to prevent an image forming apparatus from being large-sized. In particular, since the used toner drops by gravity, its taking-in structure is simplified, and the used toner can be efficiently mixed with the fresh toner irrespective of a moving direction of the toner agitating means.
In the invention it is preferable that the toner cartridge has a first film sealing member separably joined to the cartridge main body, for sealing the used toner recycling opening, and a second film sealing member separably joined to the cartridge main body, for sealing the toner supply opening, and each of free ends of the first and second film sealing members extending from their respective joining ends to an unsealing operation position by turning-up is set to an unsealing operation end, and the unsealing operation ends of the first and second film sealing members may be connected to each other either as an integral piece or by a connecting member.
According to the invention, the unsealing operation ends of the first and second film sealing members are connected to each other as described, for example, above. Accordingly, when an unsealing operation, which is an operation of pulling the connected operation ends to remove the sealing members, is performed once in replacement of the toner cartridge, both the sealing members are simultaneously separated from the cartridge main body, and the used toner recycling opening and the toner supply opening are reliably opened. Namely, with this structure it is prevented that only one of the opening portions is still in a sealing state. Further, it is sufficient to connect both the film sealing members at their unsealing operation ends after both the opening portions are sealed by the separate film sealing members at their sealing ends. Accordingly, the work of sealing the openings is easily made.
According to the invention, the toner cartridge has the first film sealing member separably joined to the cartridge main body and sealing the used toner recycling opening, and the second film sealing member separably joined to the cartridge main body and sealing the toner supply opening, and free ends of the first and second film sealing members extending from their respective joining ends to unsealing operation positions by turning-up are respectively set to unsealing operation ends, and these unsealing operation ends are connected to each other. Accordingly, when one unsealing operation using tensile force is performed, both the sealing members are simultaneously separated from the cartridge main body, and it is possible to dissolve a fear that one of the used toner recycling opening and the toner supply opening is used in error in a sealing state. Further, it is sufficient to connect both the film sealing members after both the opening portions are sealed by the separate film sealing members. Accordingly, the work of sealing the opening portions can be easily made.
In the invention it is preferable that the unsealing operation ends of the first and second film sealing members are integrally constructed for example, as a continuous piece.
According to the invention, the unsealing operation ends of the first and second film sealing members are integrally formed. Accordingly, it is not necessary to connect both the unsealing operation ends so that a manufacturing process can be simplified.
According to the invention, since the unsealing operation ends of both the first and second film sealing members are integrally formed, it is possible to omit the work of connecting the unsealing operation ends of both the film sealing members so that the manufacturing process can be simplified.
In the invention it is preferable that a contact portion is formed in a connecting portion of the unsealing operation ends of the first and second film sealing members which contact portion contacts with a portion of an outer covering member of an image forming apparatus provided with the developing apparatus, in a state where the cartridge main body is mounted to the developing apparatus to inhibit closure of the outer covering member.
According to the invention, in the mounting state of the cartridge main body to the developing apparatus, the contact portion formed in the connecting portion of the unsealing operation ends of the first and second film sealing members unseparated from the cartridge main body contacts with one portion of the outer covering member of the image forming apparatus, and cannot close the outer covering member. Accordingly, it is necessary to separate the first and second film sealing members from the cartridge main body and remove the contact portion to close the outer covering member and perform an image forming operation of the image forming apparatus. Thus, no image forming operation is executed in a sealing state of each of the used toner recycling opening and the toner supply opening. Further, no worker forgets the work of separating the first and second film sealing members from the cartridge main body.
According to the invention, in the mounting state of the cartridge main body to the developing apparatus, the contact portion formed in the connecting portion of the unsealing operation ends of the first and second film sealing members unseparated from the cartridge main body contact with one portion of the outer covering member of the image forming apparatus, and cannot close the outer covering member. Accordingly, it is possible to prevent the image forming operation from being executed in the sealing state of each of the used toner recycling opening and the toner supply opening. Further, it is possible to reliably prevent a worker from forgetting the work of removing the first and second film sealing members from the cartridge main body.
In the invention it is preferable that the cartridge main body has a winding rotating body for separating the first and second film sealing members from the cartridge main body by winding the unsealing operation ends of the first and second film sealing members.
According to the invention, when the winding rotating body is rotated, both the film sealing members are wound together so that the used toner recycling opening and the toner supply opening are easily unsealed.
According to the invention, the cartridge main body has the winding rotating body for winding the respective unsealing operation ends of both the film sealing members together. Accordingly, both the film sealing members can be wound around the winding rotating body together by rotating the winding rotating body. Therefore, it is possible to reduce an unsealing labor of the used toner recycling opening and the toner supply opening.